Pedestrians and slow-moving vehicles such as bicycles, must often share roads and highways with many types of fast-moving vehicles. In many cases, the pedestrian or slow-moving vehicle may not be visible to oncoming traffic. The pedestrian or slow moving vehicle, may not be aware of the approaching high speed traffic. This is a situation that can easily result in a serious accident.
Bicycles are typical of slow-moving vehicles with high potential for being victims of accidents with faster vehicles. Bicyclists rarely move as fast as normal highway traffic. They often are not completely aware of their surroundings due to poor visibility, helmets, wind noise, varying terrain, and other environmental factors. Most cycling traffic accidents occur either because the cyclist did not anticipate the approaching vehicle (often from the rear) or the driver of the vehicle did not see the cyclist in time to take evasive action.
In addition to cyclists, there are many other potential victims of fast-moving vehicles both on and off the road. These include pedestrians, skiers, highway workers, roller-bladders, skaters, and other personnel that must use highways, roads, or trails where visibility may be limited. Larger vehicles with limited visibility, including motorcycles, horse-drawn vehicles, and farm vehicles, may also be involved in accidents with rapidly approaching vehicles.
To reduce the possibility of accidents, slow moving, limited-visibility vehicles, and pedestrians would be aided by a proximity detector that would warn them of oncoming traffic and make the oncoming traffic aware of their presence. A vehicle proximity-alerting device could help avoid many of these potential accidents and possibly decrease the morbidity and mortality of cyclists, pedestrians, and others.
There are a large number of possible applications for a proximity detector that would warn users of oncoming traffic and make the oncoming traffic aware of their presence. The following are some examples of slow-moving and/or low-visibility road users in need of a vehicle proximity-alerting device: motorized: motorcycles, farm vehicles, construction vehicles, mail delivery vans, buses; non-motorized: bicycles, skateboards, roller blades, scooters, skates, small battery-powered cars, infant strollers, horses, horse-drawn vehicles; and pedestrian: children, walkers/joggers/runners, and highway workers.
The following are some examples of slow-moving and/or low-visibility off-road users of a vehicle proximity-alerting device: motorized: airport equipment (baggage cars, tow truck, etc.), amusement park trams, motor boats; non-motorized: off-road bicycles, row boats, sailboats; and pedestrian: skiers, and construction workers.
One example of a practical application is be a vehicle proximity-alerting device for motorcycles. Motorcycle accidents involving other vehicles are often fatal to the motorcycle rider. Although a motorcyclist is usually alert to the presence of other vehicles, it is not always the case. Also, motorcycles are often not perceived by motorists. The xe2x80x9cMotorcycle Accident Cause Factors and Identification of Countermeasures,xe2x80x9d was a study conducted by the University of Southern California (USC). With funds from the National Highway Traffic Safety Administration, researcher Harry Hurt investigated almost every aspect of 900 motorcycle accidents in the Los Angeles area.
Additionally, Hurt and his staff analyzed 3,600 motorcycle traffic accident reports in the same geographic area. Some of the findings relevant to vehicle/motorcycle accidents from the report are summarized as follows:
1. Approximately three-fourths of these motorcycle accidents involved collision with another vehicle, which was most usually a passenger automobile.
2. In the multiple-vehicle accidents, the driver of the other vehicle violated the motorcycle right-of-way and caused the accident in two-thirds of those accidents.
3. The failure of motorists to detect and recognize motorcycles in traffic is the predominating cause of motorcycle accidents. The driver of the other vehicle involved in collision with the motorcycle did not see the motorcycle before the collision, or did not see the motorcycle until too late to avoid the collision.
4. Conspicuity of the motorcycle is a critical factor in the multiple vehicle accidents, and accident involvement is significantly reduced by the use of motorcycle headlamps (on in daylight) and the wearing of high visibility yellow, orange, or bright red jackets.
5. The view of the motorcycle or the other vehicle involved in the accident is limited by glare or obstructed by other vehicles in almost half of the multiple-vehicle accidents.
Applicants proximity-alerting device is designed to accommodate a wide range of applications. For some applications, the proximity-alerting device is designed for a specific application. For example, at night a pedestrian or road worker may not require as bright a warning light as a daytime user. For this application, it is be feasible to use flashed LEDs, thereby reducing power and weight so that the detector could conveniently be worn on a person""s back.
Applicant provides approaching-vehicle proximity-alerting device designed to alert both the oncoming vehicle driver and the user of the device. Such a device includes several components. A low-power radar or another appropriate detector determines vehicle proximity (by velocity and/or distance). A flashing light is produced by the device to alert the driver of the oncoming vehicle by stimulating his visual perception. Depending on the user application (pedestrian, bicyclist, etc.), the device includes an audible, tactile and/or visual signal emitter at the same time that the driver of the oncoming vehicle is alerted by the flashing light. The vehicle-detection, visual-alert, and audible-alert circuits control and timing circuits initiate the alert upon correct detection of a vehicle. The alert device may be incorporated into other equipment such as, music earphones, heart rate monitors, and ear protection devices. Power for all circuits is supplied by internal batteries or supplied by an external power source in some applications.
The detection circuits typically consist of a simple low-power continuous wave Doppler radar. Currently, a complete RF Doppler radar module based on GUNN diode technology can be purchased commercially for approximately $75 (MA/COM Model MA87728-MO1). A similar module has a planar array and printed circuit board The detector and additional electronics, including control circuits and output circuits (audible and visual), are typically provided as a single printed circuit board.
For some applications, the device power requirements reduce the duty cycle of one or more circuits. As an example, the duty cycle of a GUNN diode radar may readily be reduced by a factor of ten. The radar may operate for ten milliseconds and be in an off state for ninety milliseconds. During the ninety milliseconds off state, an oncoming vehicle traveling at one hundred miles per hour would close by only thirteen feet. For the GUNN module previously described, the normal detection range would be on the order of about two hundred feet. Reducing the duty cycle by a factor often would reduce the range less than 7%. Similar duty cycle reduction on the other circuits may also be appropriate for some applications.
Infrared radar is provided as an alternate detector, especially for night use. Infrared radars typically use solid-state infrared laser diodes and are known as LADARs. They generally use a semiconductor diode to generate laser light. Most vehicle traffic LADARS emit laser light at around 904 nm wavelength. Other wavelengths are possible; for example, aluminum gallium arsenide (AlGaAs) diodes emit light at a wavelength of 850 nm. Gallium arsenide (GaAs), classified as an injection laser, emits light between 880 nm to 900 nm. Other wavelengths are possible using other materials or alloys.
The Federal Communications Commission (FCC) regulates radiated emissions from high-speed circuits such as the processing circuits inside a LADAR, but not infrared and light frequencies. The Federal Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) regulates laser products sold in the United States. Traffic LADARs are Class 1 devices (by American National Standards Institute definition) and considered eye-safe based on current medical knowledge.
New ultra-wideband radar technology based on very narrow pulses has the potential for providing both range and speed information using very low power. Although not commercially available at this time, there is potential for use of ultra-wideband radar as the vehicle detector for a proximity-alerting device.